<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>笑脸</title>
    <style>
        .relative {
            /* 小技巧 让有定位的盒子水平居中 垂直居中 */
            position: absolute;
            top: 50%;
            left: 50%;
            margin-top: -200px;
            margin-left: -200px;
            border-radius: 200px;
            border-top: 3px dashed #eee;
            width: 400px;
            height: 400px;
            background: rgba(238, 238, 238, .2);
            /* background-color: pink; */
        }

        .relative:hover {
            transition: border 2s;
            transition: background 4s;
            border: 1px solid rgba(255, 102, 0, 0.8);
            box-shadow: 3px 2px 7px 2px rgba(238, 238, 238, .2);
            background: rgba(255, 102, 0, 0.8);
        }

        .left {
            float: left;
            margin: 80px 0px 0px 50px;
            border-radius: 45px;
            border-top: 5px solid #eee;
            width: 90px;
            height: 90px;
            /* background-color: skyblue; */
        }

        .ragth {
            float: right;
            border-radius: 45px;
            margin: 80px 50px 0px 0px;
            border-top: 5px solid #eee;
            width: 90px;
            height: 90px;
            /* background-color: skyblue; */
        }

        .relative .center {
            margin: 210px 0px 0px 135px;
            border-radius: 65px;
            border-bottom: 10px solid #eee;
            width: 130px;
            height: 130px;
            /* background-color: hotpink; */
        }
    </style>
</head>

<body>
    <div class="relative">
        <div class="left"></div>
        <div class="ragth"></div>
        <div class="center"></div>
    </div>
</body>

</html>